Pesticides` Inert Elements Cause Concern

The next time you pick up a can of household bug spray, read the label carefully. You might note that as much as 99 percent of the product is listed only as ``inert ingredients.``

Public health officials now warn that these secret ingredients are largely unregulated and untested -- and can be just as hazardous as the active ingredients in pesticide products.

Inerts are the solvents and other substances that dissolve, propel and otherwise enhance the active ingredients in household and agricultural pesticides. Growing evidence suggests that some of these substances are highly toxic and cause thousands of the pesticide poisonings reported nationwide each year.

Some of these same toxic chemicals also are found in other consumer products, including paint remover, spray shoe polish and hair sprays. In interviews with poison control officials, government health workers and medical specialists, experts expressed concern over the widespread use of these compounds, as the compounds` health effects have not been well-studied.

The toll in poisonings from inerts in pesticides alone may be substantial. Of the 1,000 cases of pesticide poisonings logged annually at the Delaware Valley Poison Control Center in Philadelphia, ``at least 50 percent are due to inerts,`` executive director Tom Kearney says.

Corrine Ray, administrator of the Los Angeles Poison Information Center, believes inerts are causing even more poisonings. She says that nine out of 10 symptoms of household pesticide poisonings reported to her center are linked to the secret, inert ingredients -- not to the active chemicals in these compounds.

``Raid and Black Flag are made up of 20 different (chemical) products, and are up to 99 percent inert,`` Ray says. ``You can`t look at these symptoms and say they come from only 1 percent of the product.``

But industry officials insist the dangers of inerts are exaggerated. ``A significant number of the (inert) chemicals are no longer being used,`` says Ralph Engel, president of the Chemical Specialties Manufacturers Association. ``Of the ones still being used, the jury is still out`` on their potential health hazards.

``Obviously, our labels are in compliance with the law, and often go beyond the law,`` adds Pauline Grieger, public relations manager for Johnson Wax, which manufactures Raid, one of the best-selling bug sprays.

The Environmental Protection Agency estimates that at least 1,200 inerts are used in 50,000 household and agricultural pesticide formulations on the U.S. market. About 100 inerts are known or suspected health hazards, with effects ranging from cancer to central nervous system damage to serious skin rashes, according to EPA documents.

Toxicology data is lacking for an additional 800 inerts. Only about 300 inerts, or a quarter of those in use, have been cleared by the EPA as safe.

Public health officials point to several recent pesticide poisonings involving inerts that they say underscore the problem:

-- In June 1985, a 29-year-old pest control applicator named Michael London crawled under a house trailer in San Bernardino, Calif., to spray for bugs. His spray gun leaked, however, asphyxiating him and sickening three others who tried in vain to help him. A physician from the California Department of Health Services who investigated London`s death ruled that he died not from the active ingredient in his spray gun but from methylene chloride, a highly toxic carcinogen commonly added as a solvent.

-- In May of this year, in three separate incidents, 128 orange pickers in Southern California suffered severe burns and rashes after a manufacturer, Uniroyal Chemical Co., added a new inert ingredient to the pesticide Omite-CR. Uniroyal was forced to withdraw the product from the market, but the company hopes to reintroduce it with stronger use restrictions, according to state health and agricultural officials.

Compounding the problem is the fact that identities of inerts in pesticides are deliberately kept off labels by manufacturers and withheld from the public as trade secrets.

This secrecy, however, can be dangerous when a poisoning occurs. Information about product contents is sometimes not readily available to doctors, especially during non-office hours. Dr. Frank Mycroft, an environmental toxicologist with the San Francisco Bay Area Poison Center, recalls one case in which a manufacturer would not reveal the names of the inert ingredients in a product suspected of causing a poisoning. ``I still don`t know what was in the product,`` Mycroft says.